Generally, as illustrated in FIG. 14, a substrate processing apparatus includes a substrate conveyance chamber 141 equipped therein with a conveyance robot 140 configured to convey a disk-shaped semiconductor wafer W (hereinafter, simply referred to as a “wafer”) as a substrate, and a plurality of substrate processing chambers 142 arranged radially around the substrate conveyance chamber 141. In such a substrate processing apparatus, the conveyance robot 140 carries a wafer W into or from each of the substrate processing chambers 142.
Meanwhile, the wafer W is placed on a placing table 143 disposed within each of the substrate processing chambers 142. When, for example, a plasma etching processing is performed on the wafer W, it is required to exactly place the wafer W at a predetermined position on the placing table 143. Therefore, in a substrate processing apparatus, position sensors 144 for acquiring a position of the wafer W are disposed within the substrate conveyance chamber 141. Then, the wafer W is conveyed to the position sensors 144 by the conveyance robot 140, and the position of the wafer W is acquired (see, for example, Japanese Patent Laid-Open Publication No. 2007-211317). Then, when the wafer W is carried into a substrate processing chamber 142, the position of the wafer W is corrected based on the acquired position of the wafer W.